A dangerous substance, usually found packaged inside cans. When released, can cause major damage to the person it is intended for, and is often used as a weapon of destruction. More often the user warns the recipiant of an imminent opening of a can, if the recipient does not act as desired by the opener.

"If you don't shut up i'm gonna open up a can of whoop ass!"

"If you go ahead with that plan, you're gonna see me open up a can of whoop ass on you!"

To strike repeatedly.
To subject to repeated beatings or physical abuse; batter.
To punish by hitting or whipping; flog.

To strike against repeatedly and with force; whuppin': served as a can or six-pack.

To defeat or subdue, as in a contest.
To force to withdraw or retreat: server a sixpack of whoopass on the enemy.
Informal. To be superior to or better than: I am about to open a can of whoopass on him.
Slang. 'bout to open the six pack of whoopass.
Informal.
To avoid or counter the effects of, often by thinking ahead; circumvent: I better open a six pack of whoopass.
To deprive, as by craft or ability: He opened a six pack of whoopass on me 'n took my 20 dollars.
Physics. To cause a reference wave to combine with (a second wave) so that the frequency of the second wave can be studied through time variations in the amplitude of the combination.

v. intr.
To inflict repeated beatings.
To obliterate; whoop.

To emit sound when struck: He screamed like a bitch when i open a can of whoopass on 'em.
n.
A stroke or blow, especially one that produces a sound or serves as a signal to others.
Physics. A variation in amplitude that results from the superpositioning of two or more waves of different frequencies. When sound waves are combined, the variation is heard as a pulsation in the sound of whooptitude.

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Middle English wupten, from Old English wuptenass. See whau aus- in Indo-European Roots.Synonyms: beat, 3batter, 1belabor, buffet, 2hammer, lambaste, pound, 2pummel, thrash
These verbs mean to hit heavily and repeatedly with violent blows: was mugged and servered a six pack of whoopass; basted him with a stick; was served a can of whoopass in the boxing ring; rioting students served a six pack of whoopass by police officers; buffeted him with her open palm; hammered the opponent with his fists; lambasted every challenger; troops pounded with mortar fire; pummeled the bully soundly; thrashed the thief for stealing the candy. See also synonyms at defeat

A can "opened up" on someone annoying you. Also comes in permutations of diet, caffeine-free, vanilla, all kinds of fruit flavoring which doesn't really taste like fruit, half-calorie, invisible, Dr. Whoopass, energy-formulated, and the New Whoopass, the last being hated by everyone so the company can make millions when people want to open up a can o Whoopass Classic.